Abstract

This study provides the first assemblage-based taxonomic revision of the mollusk fauna of the Middle Miocene Dinaride Lake System (DLS). The assemblage, consisting of more than 13.000 specimens, was sampled from a 100-m-thick Lower Langhian interval of the Lučane section in the Sinj Basin (Croatia). 18 gastropod species and 3 bivalve species are detected from the succession. All are endemic to the Dinaride Lake System. Within that system, the described fauna of Lake Sinj displays strong similarities with the coeval and geographically close fauna of Lake Drniš. Reduced faunistic relations to other lakes of the DLS are discussed to result from slightly different stratigraphic ages and deviating paleoecologic settings. Many melanopsid and prososthenid gastropod taxa in the literature are considered to be mere morphotypes of few polymorphic species resulting in nomenclatorial rectifications.Melanopsis lucanensis Neubauer n. sp. and Belgrandia klietmanni Neubauer n. sp. are introduced as new species.